Process of manufacturing producer gas of high calorific value



June 26, 1934. KOLLER 5 AL 1,964,207

PROCESS OF MANUFACTURING PRODUCER GAS OF HIGH CALORIFIC VALUE Filed Nov. 28, 1930 l' y x INNeNTo Patented June 26, 1934 UNITED STATES PROCESS OF MANUFACTURING PRODUCER GAS OF HIGH CALORIFIC VALUE Karl Koller and-Zsigmond Galocsy, Budapest, Hungary Application November 2 In H ' 4 Claims.

Endeavours have been made for many years to make producer gas of high calorific value, e. g. water gas, double gas etc. with the aid of oxygen in continuous operation, but the experiments so 5 far have not been quite successfuh, The first reason for this is that using oxygen for the gasification of the fuel, the temperature in the lower zone of the producer will mount too high, exceeding in many cases even 2000 (3., at which temperature even the most heat resisting bricks will melt. If we wish to protect the lining we must conduct to the producer a larger quantity of steam than necessary for the right reactions, and the surplus steam will help the production of carbon dioxide and thus reduce greatly the calorific value of the gas. The thermodynamical reason of this phenomenon is that sufficient time is not available for effecting a. diffusion of heat sumcient to raise the temperature of the steam to a level corresponding to the reaction temperature, and that therefore the largest part of the excess heat available is used for superheating the steam to a high degreeinstead of causing the endothermic dissociation of the steam to be effected; the further consequence of this is that the superheated steam will help the production of carbon dioxide in consequence of the exothermic reaction taking place in the upper zones of the coal column.

Now, we found that this drawback which up to now has rendered the manufacturing of producer gas of high calorific value by means of oxygen nearly impossible, can be eliminated by introducing into the producer a sufficient quantity of steam to maintain the water-gas reaction, superheated to a temperature exceeding the tempera-' ture of the reaction zone, in such a manner as to ensure that the excess quantities of heat are utilized mostly for effecting the endothermic dissociation of steam which is useful for the watergas reaction. It is however, impossible to effect the superheating of steam to so high temperatures in regenerators, recuperators or superheaters.

According to the invention it is possible to effect the superheating of the steam to such a degree, if the production of the producer gas of high calorific value is carried out in two separate partial processes. In the first process any kind of solid, liquid or gaseous fuel is burnt by means of oxygen, air, or air enriched by oxygen in a combustion chamber being in direct connection with the producer proper, and the flue gases are mixed with saturated or previously superheated.- steam whereas the steam will be superheated close 7 8, 1930, Serial No. 498,905 ungary November 28, 1929 to the temperature of the flue gases. In the second process the mixture of flue gases and of superheated steam will pass through the incandescent fuel column of a producer operating with liquid slag, where the reduction of the carbon dioxide of the flue gases and the dissociation of steam into its elements, i. e. the gas generating, is efiected. Accordingly, the gasification of the fuel is effected with the aid of oxygen, but the largest part ofoxygen is not conducted to the producer directly, but through oxygen carriers as carbon dioxide and steam. In order to increase the speed of reaction it is preferable to keep the combustion chamber and the producer under pressure.

According to the invention, therefore, two kinds of fuels are used for manufacturing producer gas of high calorific value, notably primary fuel whichis burnt in the first partial process, and secondary fuel which is gasified in the second partial process. The primary fuel may be of any physical condition or kind whatever. Thus, we can use any fuel of inferior value as coaldust, sawdust, also oil, tar, and even gas. Green lignites, peat etc. are advantageous, since this kind of fuel contains a large proportion of free oxygen which partly will provide the quantity of oxygen necessary for combustion and for the gasification, and of twdrogen, moisture and boimd water by which the quantity of separately produced steam can be reduced. It is also possible to use with advantage as a primary fuel, for instance, ordinary producer gas made from the kinds of fuel referred to. As secondary fuel any kind of sized fuel, suitable for being gasified as e. g. coal, coke, wood etc. may be used.

The heat radiated by the combustion chamber in which the combustion of the primary fuel is effected may also be utilized for generating steam. 96 The steam thus generated can subsequently be used for the purposes of the plant for producing oxygen to be utilized for the-combustion, or for the purposes of any kind of power plant, the exhaust steam of such plants being used for providmo ing the steam required for the process of producing gas.

According to the invention it is possible to make producer gas of high calorific value in continuous operation and under the best conditions regarding the thermal economy in a producer operating with liquid slag. The produced gas can be utilized even as fighting gas, if desired' By means of this process, it is possible to utilize fuels of poor quality which so far could not be used for making producer gas and particularly producer gas of high calorific value.

On account of the two partial processes we are able.to use two different kinds of fuel, also it is easy to control the operation of the producer, and it is possible to satisfy the requirements of synthetic chemical industry in regard to the quality of the producer gas.

A further advantage is thatthe slag does not contain combustible parts. Further, it is also possible according to the invention to vary the chemical constitution of the liquid slag by the addition of slag-forming charges, to enable it to be utilized as a hydraulic cementing material.

In the case that a producer gas with high percentage of carbon monoxide is required, the fiue gases will be mixed in the first partial process with carbon dioxide instead of or in addition to the steam.

In the accompanying drawing is shown diagrammatically an apparatus for carrying out the process of the present invention. Figure 1 is a vertical section of the apparatus and Fig. 2 a horizontal section along the line 22 of Fig. 1.

On the drawing A is the gas producer, B the combustion chamber which is connected with the producer through the passage C. The passage C opens into an annular passage D from which the radial passages E lead into the gas producer shaft. In this example the primaryjuel is generator gas which is supplied to the combustion chamber B together with oxygen and steam through the burner F. In the combustion chamber takes place the combustion of the primary fuel, that is generator gas, and also the mixing of the flue gases with steam, consequently the high super-heating of the steam. The combustion products pass, if necessary, with an excess of oxygen, through the connecting passage C into the annular passage D, from which they arrive through the radial passages E uniformly distributed into the gas generator shaft, and then gasify the coal in the gas generator A in the usual manner.

What we claim is:

1. Process of manufacturing producer gas of high calorific value in a continuous uni-directional flow, said process being carried out in two stages, the first stage comprising the burning of suitable fuel with oxygen and mixing the resulting flue gases with steam, thereby preheating the steam to approximately the temperature of the flue gases; the second stage comprising introducing the hot mixture without cooling, directly into the lower part of a column of incandescent solid fuel in a molten slag producer and withdrawing the resulting combustible gas from the upper part of the column.

2. Process of manufacturing producer gas of high calorific value in a continuous uni-directional flow, said process being carried out in two stages, the first stage comprising the burning of suitable fuel with oxygen and mixing the resulting flue gases with steam and carbon dioxide, thereby preheating the steam to approximately the temperature of the fiue gases; the second stage comprising introducing the hot mixture without cooling, directly into the lower part of a column of incandescent solid fuel in a molten slag producer and withdrawing the resulting combustible gas from the upper part of the column.

3.Process of manufacturing producer gas of high calorific value in a continuous uni-directional flow, said process being carried out in two stages, the first stage comprising the burning of suitable fuel with air enriched by oxygen and mixing the resulting flue gases with steam, thereby preheating the steam to approximately the temperature of the flue gases; the second stage comprising introducing the hot mixture without cooling, directly into the lower part of a column of incandescent solid fuel in a molten slag producer and withdrawing the resulting combustible gas from the upper part of the column.

4.-Process of manufacturing producer gas of high calorific value in a continuous uni-directional flow, said process being carried out in two stages, the first stage comprising the burning of suitable fuel with air enriched by oxygen and mixing the resulting fiue gases with steam and carbon dioxide, thereby preheating the steam to approximately the temperature of the flue gases; the second stage comprising introducing the hot mixture without cooling, directly into the lower part of a column of incandescent solid fuel in a molten slag producer and withdrawing the resulting combustible gas from the upper part of the column.

KARL KOLLER. ZSIG'MOND GALocsY. 

